1. Field of the Invention
This invention relates to the art of airless blast cleaning equipment and more particularly to apparatus of the type which include a rotating wheel with blades that forcefully propel a stream of abrasive particles for impingement against a workpiece.
2. History of the Prior Art
Centrifugal blasting machines are well-known in the prior art. Such machines typically have a motor-driven rotating throwing wheel with a plurality of blade members disposed along radii of the wheel. The wheel is usually constructed of two outer discs, each of which has opposing radial grooves which receive the throwing blades and include means for locking such blades in position to prevent their dislodgement during operation. These blades are subject to substantial wear and must be replaced periodically. The abrasive particles usually enter the wheel through a supply conduit running into the wheel's hub. An impellor is mounted in this central hub opening adapted to rotate with the wheel and to direct the abrasive particles through an opening in a surrounding control cage onto the face of each blade in turn. Around portions of the wheel may be replaceable wear plates.
Examples of such blasting machines are disclosed in the following U.S. patents:
U.S. Pat. No. 2,132,311 to Minich PA1 U.S. Pat. No. 3,319,383 to A. E. Bowling PA1 U.S. Pat. No. 3,566,644 to Moore PA1 U.S. Pat. No. 3,867,791 to Goff